The accuracy of the vision system is as described in the table below and depends on the robot model used. It is valid for the area where the calibration board was located during the calibration process.
Table 7.3.1: Accuracy of the vision system.
Calibration board position
Figure 7.3.1 : Calibration board position.
|Maximum board distance (cm)||26||34||42|
|Minimum board distance (cm)||42||70||98|
Snapshot Position will determine the field of view, notice that the calibration step position does not have to be the same as Snapshot position. Thus, you can have a small field of view, then move back for calibration step.
Field of view
|Maximum field of view (cm)||36 x 27||64 x 48||100 x 75|
|Minimum field of view (cm)||10 x 7.5||10 x 7.5||10 x 7.5|
The maximum part size that can be detected by the Wrist Camera is 60% field of view's dimension. The minimum is 10%, no matter the robot or the field of view size.
Figure 7.3.2 : Maximum and minimum part size.
The part must not be higher than its smallest dimension (width or length) : maximum of 1:1 ratio.
Figure 7.3.3 : Maximum part height.
Part height ratio is taken between the maximum part height at any point and the minimum dimension present on part contour, width or length.
To ensure a good model and part detection from the Vision system, you should use a background that has a high color contrast with the part to be detected. You must choose colors that are apart horizontally on the HSV cone shown below. Therefore, a change in value (intensity) only does not represent a good contrast. There has to be a great difference in hue and saturation to obtain a good object model from the object teaching wizard. You can use either the yellow or pink side of the colored background provided with the camera kit. If required, use a different colored background to teach your part.
Figure 7.3.4 : HSV color cone.